Combination of FDG-PET and UCSF Criteria for Predicting HCC Recurrence After Living Donor Liver Transplantation. Transplantation. 2016;100:1925-1932. [PMID: 27306534 DOI: 10.1097/tp.0000000000001297]

Sequential living donor liver transplantation after liver resection optimizes outcomes for patients with high-risk hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality. While liver transplantation (LT) provides the best long-term survival, it is constrained by organ scarcity and strict criteria. Liver resection (LR) is often the initial treatment for patients with solitary tumors and preserved liver function. The high recurrence rates associated with LR has prompted the exploration of sequential living donor liver transplantation (seqLDLT) after LR as a strategy for HCC patients with high-risk of recurrence.

METHODS

We analyzed data from 27 adult patients who underwent seqLDLT after LR for HCC at Kaohsiung Chang Gung Memorial Hospital (KCGMH) between June 1994 and December 2023. Patients were selected based on high-risk histopathological features post-LR or as part of downstaging strategy. Outcomes measured included overall survival (OS) and disease-free survival (DFS).

RESULTS

Among 765 HCC patients who underwent LDLT, 204 received LR before LDLT, and 27 underwent seqLDLT. Five patients (19%) underwent living donor liver transplantation (LDLT) following LR as a downstaging strategy while the rest received seqLDLT as a preemptive strategy. The median age was 53.5 years with 85% males. Chronic hepatitis B was the predominant underlying disease (74%). The 1-, 3-, and 5-year OS and DFS rates were 100%, 96.0%, 96.0% and 100%, 96.2%, 96.2%, respectively, with two patients experiencing HCC recurrence. One patient died from HCC recurrence. High-risk histopathological features included microvascular invasion (52%), satellite nodules (15%), multiple tumors (26%), tumors > 5 cm (19%), and a total tumor diameter > 10 cm (7%).

CONCLUSIONS

SeqLDLT offers a promising, tailored approach for managing HCC with adverse histopathologic features. Combining seqLDLT, downstaging strategies, and multidisciplinary treatments can achieve satisfactory OS and DFS in carefully selected patients, highlighting the need for refined criteria to identify the best candidates.

Tata Memorial Centre Evidence Based Use of Nuclear medicine diagnostic and treatment modalities in cancer

ABSTRACT

PET/CT and radioisotope therapy are diagnostic and therapeutic arms of Nuclear Medicine, respectively. With the emergence of better technology, PET/CT has become an accessible modality. Diagnostic tracers exploring disease-specific targets has led the clinicians to look beyond FDG PET. Moreover, with the emergence of theranostic pairs of radiopharmaceuticals, radioisotope therapy is gradually making it's way into treatment algorithm of common cancers in India. We therefore would like to discuss in detail the updates in PET/CT imaging and radionuclide therapy and generate a consensus-driven evidence based document which would guide the practitioners of Oncology.

Predicting Outcome after Percutaneous Ablation for Early-Stage Hepatocellular Carcinoma Using Various Imaging Modalities

Percutaneous ablation is a low-invasive, repeatable, and curative local treatment that is now recommended for early-stage hepatocellular carcinoma (HCC) that is not suitable for surgical resection. Poorly differentiated HCC has high-grade malignancy potential. Microvascular invasion is frequently seen, even in tumors smaller than 3 cm in diameter, and prognosis is poor after percutaneous ablation. Biopsy has a high risk of complications such as bleeding and dissemination; therefore, it has limitations in determining HCC tumor malignancy prior to treatment. Advances in diagnostic imaging have enabled non-invasive diagnosis of tumor malignancy. We describe the usefulness of ultrasonography, computed tomography, magnetic resonance imaging, and 18F-fluorodeoxyglucose positron emission tomography for predicting outcome after percutaneous ablation for HCC.

Impact of metabolic indices of 18F-fluorodeoxyglucose positron emission tomography/computed tomography on post transplantation recurrence of hepatocellular carcinoma

BACKGROUND

Tumor recurrence is the leading cause of death after liver transplantation in patients with hepatocellular carcinoma. There is an ongoing debate as to whether metabolic indices such as tumor to liver standardized uptake value ratio in ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography of the primary tumor can identify patients outside the Milan criteria with as low recurrence rates as patients inside Milan and thus should be added to the established prognostic factors.

METHODS

This retrospective study analyzes 103 consecutive patients who underwent ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography before liver transplantation for hepatocellular carcinoma using data of clinical tumor registry. Primary endpoints were overall survival and 10-year cumulative recurrence rates.

RESULTS

Tumor to liver standardized uptake value ratio of the primary tumor was statistically significant higher in Milan out tumors, "up-to-seven" out tumors, grade 3 tumors, α- fetoprotein level >400 ng/ml and lesions > 5cm in diameter. Factors with statistically significant influence on the 10- year overall survival in the univariate analysis were Milan, up-to-seven" criteria, number of lesions and pT-category. COX regression analysis did not show independently statistically significant factors for 10-year overall survival. Milan, "up-to-seven" criteria, grade, pV, number of lesions, size of lesion, pT-category, tumor to liver standardized uptake value ratio influenced 10-year cumulative recurrence rates statistically significant. Tumor to liver standardized uptake value ratio, grade and pT-category proved to be independently statistically significant factors for 10-year cumulative recurrence rates.

CONCLUSIONS

Our study suggests that tumor to liver standardized uptake value standardized uptake value ratio in ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography is an independent prognostic factor in transplanted patients with hepatocellular carcinoma. If we focus on preoperative findings, such as tumor size, tumor number and AFP value adding the information given by TLR of ¹⁸F-FDG PET/CT allows to estimate the risk of tumor recurrence more accurate than the established classifications Milan and UTS. Therefore, it may add valuable information to other preoperative findings, such as tumor size, tumor number and AFP level.

Predicting Overall Survival with Deep Learning from 18F-FDG PET-CT Images in Patients with Hepatocellular Carcinoma before Liver Transplantation

Positron emission tomography and computed tomography with 18F-fluorodeoxyglucose (18F-FDG PET-CT) were used to predict outcomes after liver transplantation in patients with hepatocellular carcinoma (HCC). However, few approaches for prediction based on 18F-FDG PET-CT images that leverage automatic liver segmentation and deep learning were proposed. This study evaluated the performance of deep learning from 18F-FDG PET-CT images to predict overall survival in HCC patients before liver transplantation (LT). We retrospectively included 304 patients with HCC who underwent 18F-FDG PET/CT before LT between January 2010 and December 2016. The hepatic areas of 273 of the patients were segmented by software, while the other 31 were delineated manually. We analyzed the predictive value of the deep learning model from both FDG PET/CT images and CT images alone. The results of the developed prognostic model were obtained by combining FDG PET-CT images and combining FDG CT images (0.807 AUC vs. 0.743 AUC). The model based on FDG PET-CT images achieved somewhat better sensitivity than the model based on CT images alone (0.571 SEN vs. 0.432 SEN). Automatic liver segmentation from 18F-FDG PET-CT images is feasible and can be utilized to train deep-learning models. The proposed predictive tool can effectively determine prognosis (i.e., overall survival) and, thereby, select an optimal candidate of LT for patients with HCC.

The "No-touch" technique improves the survival of patients with advanced hepatocellular carcinomas treated by liver transplantation: A single-center prospective randomized controlled trial

BACKGROUND

Liver transplantation (LT) is the best treatment for patients with hepatocellular carcinoma (HCC). However, the surgical technique needs to be improved. The present study aimed to evaluate the "no-touch" technique in LT.

METHODS

From January 2018 to December 2019, we performed a prospective randomized controlled trial on HCC patients who underwent LT. The patients were randomized into two groups: a no-touch technique LT group (NT group, n = 38) and a conventional LT technique group (CT group, n = 46). Operative outcomes and survival in the two groups were analyzed.

RESULTS

The perioperative parameters were comparable between the two groups (P > 0.05). There was no significant difference between the two groups in disease-free survival (DFS) (P = 0.732) or overall survival (OS) (P = 0.891). Of 36 patients who were beyond the Hangzhou criteria for LT, the DFS of the patients in the NT group was significantly longer than that in the CT group (median 402 vs. 126 days, P = 0.025). In 31 patients who had portal vein tumor thrombosis (PVTT), DFS and OS in the NT group were significantly better than those in the CT group (median DFS 420 vs. 167 days, P = 0.022; 2-year OS rate 93.8% vs. 66.7%, P = 0.043). In 14 patients who had diffuse-type HCCs, DFS and OS were significantly better in the NT group than in the CT group (median DFS 141 vs. 56 days, P = 0.008; 2-year OS rate 75.0% vs. 33.3%, P = 0.034). Multivariate analysis showed that for patients with PVTT and diffuse-type HCCs, the no-touch technique was an independent favorable factor for OS (PVTT: HR = 0.018, 95% CI: 0.001-0.408, P = 0.012; diffuse-type HCCs: HR = 0.034, 95% CI: 0.002-0.634, P = 0.024).

CONCLUSIONS

The no-touch technique improved the survival of patients with advanced HCC compared with the conventional technique. The no-touch technique may provide a new and effective LT technique for advanced HCCs.

Liver Transplantation for Hepatocellular Carcinoma: How Should We Improve the Thresholds?

Simple Summary

The ideal treatment for hepatocellular carcinoma (HCC) is liver transplantation (LT), which both eliminates the HCC and cures the diseased liver. Once considered an experimental treatment with dismal survival rates, LT for HCC entered a new era with the establishment of the Milan criteria over 20 years ago. However, over the last two decades, the Milan criteria, which are based on tumor morphology, have come under intense scrutiny and are now largely regarded as too restrictive, and limit the access of transplantation for many patients who would otherwise achieve good clinical outcomes. The liver transplant community has been making every effort to reach a goal of establishing more reliable selection criteria. This article addresses how the criteria have been extended, as well as the concept of pre-transplant down-staging to maximize the eligibility.

Abstract

Hepatocellular carcinoma (HCC) is the third highest cause of cancer-related mortality, and liver transplantation is the ideal treatment for this disease. The Milan criteria provided the opportunity for HCC patients to undergo LT with favorable outcomes and have been the international gold standard and benchmark. With the accumulation of data, however, the Milan criteria are not regarded as too restrictive. After the implementation of the Milan criteria, many extended criteria have been proposed, which increases the limitations regarding the morphological tumor burden, and incorporates the tumor’s biological behavior using surrogate markers. The paradigm for the patient selection for LT appears to be shifting from morphologic criteria to a combination of biologic, histologic, and morphologic criteria, and to the establishment of a model for predicting post-transplant recurrence and outcomes. This review article aims to characterize the various patient selection criteria for LT, with reference to several surrogate markers for the biological behavior of HCC (e.g., AFP, PIVKA-II, NLR, 18F-FDG PET/CT, liquid biopsy), and the response to locoregional therapy. Furthermore, the allocation rules in each country and the present evidence on the role of down-staging large tumors are addressed.

Role of Pretransplant Treatments for Patients with Hepatocellular Carcinoma Waiting for Liver Transplantation

Simple Summary

Hepatocellular carcinoma (HCC) is the fifth most common cancer in men worldwide and the second leading cause of cancer death. Liver transplantation (LT) is one of the treatment options for patients with HCC. Recently, there have been many reports of the usefulness of locoregional therapy, such as transarterial chemoembolization and radiofrequency ablation, for HCC as pretreatment before LT. In Western countries, locoregional therapy is used to bridge until transplantation to prevent drop-outs from the waiting list or for downstaging to treat patients with advanced HCC who initially exceed the criteria for LT. With the progress of locoregional therapy, new reports on the effects of bridging and downstaging locoregional therapy as pretransplant treatment are increasing in number.

Abstract

Recently, there have been many reports of the usefulness of locoregional therapy such as transarterial chemoembolization and radiofrequency ablation for hepatocellular carcinoma (HCC) as pretreatment before liver transplantation (LT). Locoregional therapy is performed with curative intent in Japan, where living donor LT constitutes the majority of LT due to the critical shortage of deceased donors. However, in Western countries, where deceased donor LT is the main procedure, LT is indicated for early-stage HCC regardless of liver functional reserve, and locoregional therapy is used for bridging until transplantation to prevent drop-outs from the waiting list or for downstaging to treat patients with advanced HCC who initially exceed the criteria for LT. There are many reports of the effect of bridging and downstaging locoregional therapy before LT, and its indications and efficacy are becoming clear. Responses to locoregional therapy, such as changes in tumor markers, the avidity of FDG-PET, etc., are considered useful for successful bridging and downstaging. In this review, the effects of bridging and downstaging locoregional therapy as a pretransplant treatment on the results of transplantation are clarified, focusing on recent reports.

Predicting the Recurrence of Hepatocellular Carcinoma after Primary Living Donor Liver Transplantation Using Metabolic Parameters Obtained from 18F-FDG PET/CT

This study evaluated the prognostic value of metabolic parameters based on the standardized uptake value (SUV) normalized by total body weight (bwSUV) and by lean body mass (SUL) measured on ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) for predicting tumor recurrence after primary living donor liver transplantation (LDLT) in patients with hepatocellular carcinoma (HCC) without transplantation locoregional therapy. This retrospective study enrolled 49 patients with HCC. The maximum tumor bwSUV (T-bwSUVmax) and SUL (T-SULmax) were measured on PET. The maximum bwSUV (L-bwSUVmax), mean bwSUV (L-bwSUVmean), maximum SUL (L-SULmax), and mean SUL (L-SULmean) were measured in the liver. All metabolic parameters were evaluated using survival analyses and compared to clinicopathological factors. Tumor recurrence occurred in 16/49 patients. Kaplan–Meier analysis revealed that all metabolic parameters were significant (p < 0.05). Univariate analysis revealed that prothrombin-induced by vitamin K absence or antagonist-II; T-stage; tumor number; tumor size; microvascular invasion; the Milan criteria, University of California, San Francisco (UCSF), and up-to-seven criteria; T-bwSUVmax/L-bwSUVmean; T-SULmax; T-SULmax/L-SULmax; and T-SULmax/L-SULmean were significant predictors. Multivariate analysis revealed that the T-SULmax/L-SULmean (hazard ratio = 115.6; p = 0.001; cut-off, 1.81) and UCSF criteria (hazard ratio = 172.1; p = 0.010) were independent predictors of tumor recurrence. SUL-based metabolic parameters, especially T-SULmax/L-SULmean, were significant, independent predictors of HCC recurrence post-LDLT.

Hepatocellular cancer selection systems and liver transplantation: from the tower of babel to an ideal comprehensive score

The Milan criteria (MC) remain the cornerstone for the selection of patients with hepatocellular cancer (HCC) to be listed for liver transplantation (LT). Recently, several expanded criteria have been proposed to increase the transplantability of HCC patients without compromising their (oncologic) outcome. This paper aims to systematically review the different reported HCC-LT selection systems looking thereby at their ability to increase the number of transplantable patients and the overall survival and oncological outcome. A systematic review of the literature covering the period 1993 (date of the first reported HCC-LT selection system)-2021 identified 59 different inclusion criteria of HCC for LT. Among the 59 studies reporting HCC-LT selection systems, 15 (28.3%) were exclusively based on morphological aspects of the tumor; 29 (54.7%) included biologic, seven (13.2%) radiological, and two (3.8%) only included pathological tumor features. Overall, 31% more patients could be transplanted when adhering to the new HCC-LT selection systems. Despite the increased number of LT, 5-year patient and disease-free survival rates were similar between MC-IN and MC-OUT/new HCC-LT-IN criteria. A careful extension of the inclusion criteria should allow many more patients to access a potentially curative LT without compromising their outcome. The development of a widely accepted "comprehensive" HCC-LT Score able to offer a fair chance of justified transplantation to more patients should become a priority within the liver transplant community. Further studies are needed to develop internationally accepted, expanded selection criteria for liver transplantation of HCC patients.

Immunological Markers, Prognostic Factors and Challenges Following Curative Treatments for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related mortalities worldwide. Patients with early-stage HCC are eligible for curative treatments, such as surgical resection, liver transplantation (LT) and percutaneous ablation. Although curative treatments provide excellent long-term survival, almost 70-80% of patients experience HCC recurrence after curative treatments. Tumor-related factors, including tumor size, number and differentiation, and underlying liver disease, are well-known risk factors for recurrence following curative therapies. Moreover, the tumor microenvironment (TME) also plays a key role in the recurrence of HCC. Many immunosuppressive mechanisms, such as an increase in regulatory T cells and myeloid-derived suppressor cells with a decrease in cytotoxic T cells, are implicated in HCC recurrence. These suppressive TMEs are also modulated by several factors and pathways, including mammalian target of rapamycin signaling, vascular endothelial growth factor, programmed cell death protein 1 and its ligand 1. Based on these mechanisms and the promising results of immune checkpoint blockers (ICBs) in advanced HCC, there have been several ongoing adjuvant studies using a single or combination of ICB following curative treatments in HCC. In this review, we strive to provide biologic and immunological markers, prognostic factors, and challenges associated with clinical outcomes after curative treatments, including resection, LT and ablation.

Diagnostic test accuracies of F-18 FDG PET/CT for prediction of microvascular invasion of hepatocellular carcinoma: A meta-analysis

PURPOSE

The aim of the current meta-analysis was to evaluate diagnostic accuracies of preoperative F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) or positron emission tomography/computed tomography (PET/CT) for prediction of microvascular invasion (MVI) in hepatocellular carcinoma (HCC) patients.

METHODS

The scientific database such as PubMed, Cochrane, and Embase database were searched for studies evaluating diagnostic accuracies of preoperative F-18 FDG PET or PET/CT for prediction of MVI in HCC patients up to November 30, 2020.

RESULTS

Fourteen eligible studies (1276 patients) were enrolled. The pooled sensitivity for F-18 FDG PET or PET/CT was 0.67 (95% CI; 0.57-0.76) with heterogeneity and a pooled specificity of 0.80 (95% CI; 0.74-0.85) with heterogeneity. Likelihood ratio (LR) syntheses gave an overall positive likelihood ratio (LR+) of 3.3 (95% CI; 2.5-4.5) and negative likelihood ratio (LR-) of 0.41 (95% CI; 0.31-0.55). The pooled diagnostic odds ratio (DOR) was 8 (95% CI; 5-14). Summary receiver operating characteristic (ROC) curve indicates that the area under the curve was 0.81 (95% CI; 0.78-0.84).

CONCLUSION

The current meta-analysis showed a low sensitivity and moderate specificity of F-18 FDG PET or PET/CT for the prediction of MVI in HCC patients. F-18 FDG PET or PET/CT might not be useful for the preoperative prediction of MVI in HCC patients and should not be used to exclude MVI. Therefore, cautious application and interpretation should be paid to the F-18 FDG PET or PET/CT for the prediction of MVI in HCC patients preoperatively.

Investigating the value of pre-treatment 18F-FDG PET/CT in predicting the pathological characteristic of hepatocellular carcinoma and recurrence after liver transplantation

PURPOSE

The aim of this study is to investigate the value of pre-treatment ¹⁸F-FDG PET/CT in predicting the pathological characteristic of HCC and recurrence after liver transplantation (LT).

METHODS

A total of 34 patients who underwent ¹⁸F-FDG PET/CT before LT for HCC and did not receive any other treatment were retrospectively enrolled in the study. The maximal standard uptake value of the tumor (T-SUVmax), normal liver tissues (L-SUVmax), and mediastinal blood pool (B-SUVmax) were derived, followed by the calculations of the T-SUVmax/L-SUVmax (T/L) and the T-SUVmax/B-SUVmax (T/B) ratios. Combined with the post-transplantation pathological results and ROC curve, the performance in predicting the pathological characteristic and the recurrence after LT were evaluated.

RESULTS

The AUCs for T-SUVmax, T/L, and T/B in predicting the pathological grade of tumors were 0.820, 0.784, and 0.806, respectively. Alternatively, the AUCs for T-SUVmax, T/L, and T/B in predicting the recurrence after LT were 0.865, 0.899, and 0.931, respectively. The individual cutoff values were 5.0, 1.7, and 2.2, corresponding to a predication accuracy of 88.2%, 85.3%, and 88.2%, respectively. In addition, the AUCs for T/B in predicting microvascular invasion (mVI) and liver capsular invasion (LCI) were 0.825 and 0.788, respectively.

CONCLUSION

The pre-treatment ¹⁸F-FDG PET/CT is effective for predicting recurrence of HCC after LT. In addition, it demonstrates values for predicting the pathological characteristic of HCC such as pathological grade, mVI, and LCI.

Liver Living Donation for Cancer Patients: Benefits, Risks, Justification

LDLT covers all standard indications for liver transplantation, and the results are similar or even better than for standard DDLT. Due to the donor shortage and long waiting time, LDLT has become a relevant option for patients with liver tumors, provided the expected five-year survival rate is comparable to that of patients receiving a DDLT. Nowadays, LDLT offers the possibility to extend the standard morphometric selection by considering the biological parameters. In the setting of LDLT, we are not only faced with surgical morbidity in the donor, but long-term non-medical problems like psychological complications and financial burden also have to be considered. On the other hand, the benefits to the donor are mainly social and psychological. In LDLT, the donor's altruism is the fundamental ethical principle and it is based on the principles of (1) beneficence (doing good), (2) non-maleficence (avoiding harm), (3) respect for autonomy, and (4) respect for justice (promoting fairness). On top of that, the concept of double equipoise of living organ donation evaluates the relationship between the recipient's need, the donor's risk, and the recipient's outcome. It considers each donor-recipient pair as a unit, analyzing whether the specific recipient's benefit justifies the specific donor's risk in particular oncologic indications. In this light, it is essential to seek adequate informed consent focused on risk, benefits and outcome benefits of both donor and recipient supported by an independent living donor advocate. Finally, the transplant team must protect donors from donation if harm does not justify the expected benefit to the recipient.

The Key Role of Staging Definitions for Assessment of Downstaging for Hepatocellular Carcinoma

The success of liver transplant (LT) for hepatocellular carcinoma (HCC) is dependent on accurate tumor staging using validated imaging criteria, and adherence to acceptable criteria based on tumor size and number. Other factors including α-fetoprotein (AFP) and response to local regional therapy (LRT) have now played a larger role in candidate selection. Tumor downstaging is defined as reduction in the size of viable tumors using LRT to meet acceptable criteria for LT, and serves as a selection tool for a subgroup of HCC with more favorable biology. The application of tumor downstaging requires a structured approach involving three key components in tumor staging-initial tumor stage and eligibility criteria, tumor viability assessment following LRT, and target tumor stage prior to LT-and incorporation of AFP into staging and treatment response assessments. In this review, we provide in-depth discussions of the key role of these staging definitions in ensuring successful outcome.

An FDG PET/CT metabolic parameter-based nomogram for predicting the early recurrence of hepatocellular carcinoma after liver transplantation

PURPOSE

To construct an FDG PET/CT metabolic parameter-based model to predict early recurrence of hepatocellular carcinoma (HCC) after liver transplantation (LT).

METHODS

A total of 62 patients with HCC after LT were enrolled with a follow-up period of 1 year. Basic clinical, pathology, and laboratory data, CT features (CPLC), and PET metabolic parameters (CPLCP) were collected for model construction. A CPLC nomogram without metabolic parameters and a CPLCP nomogram with metabolic parameters were established. The net reclassification index (NRI) and integrated discrimination improvement (IDI) of the two models were calculated. The constructed model was compared with Milan criteria and University of California San Francisco (UCSF) criteria. The time-dependent area under the receiver operating characteristic curve (time-AUC) was used to compare the efficiency of the models, and the bootstrap method was used to for verification. Harrell's concordance index (C-index) was used to evaluate the performance of these models. Decision curve analysis (DCA) was used to evaluate the clinical practicability of each model.

RESULTS

Thirty out of 62 patients experienced a recurrence during the 1-year follow-up. BCLC stage (P = 0.009), MVI (P = 0.032), AFP (P = 0.004), CTdmax (P = 0.033), and MTV (P = 0.039) were the independent predictors. The CPLC nomogram and the CPLCP nomogram were established. Compared with the CPLC nomogram, the NRI of the CPLCP nomogram increased by 38.98% (95% CI = -18.77-60.43%) and the IDI increased by 4.40% (95% CI = -1.00-16.62%). The AUC value of the CPLCP nomogram was higher than those of Milan criteria and UCSF criteria in the time-AUC curve. Moreover, the CPLCP nomogram had a higher C-index (0.774) than other models. Finally, the DCA curve showed that clinical practicability of the CPLCP nomogram outperformed the Milan criteria and UCSF criteria.

CONCLUSIONS

The CPLCP nomogram combining basic clinical data, pathology data, laboratory data, CT features, and PET metabolic parameters showed good efficacy and high clinical practicability in predicting the early recurrence of HCC after LT.

Experience With LDLT in Patients With Hepatocellular Carcinoma and Portal Vein Tumor Thrombosis Postdownstaging

BACKGROUND

Median survival in patients with hepatocellular carcinoma (HCC) and portal vein tumor thrombosis (PVTT) is 2-6 months; conventionally liver transplantation is contraindicated.

METHODS

We studied outcomes following living donor liver transplantation (LDLT) post-PVTT downstaging (DS) with stereotactic body radiotherapy (SBRT), and tumor ablation (with transarterial chemo- or radio-embolization).

RESULTS

Of 2348 consecutive LDLTs, 451 were for HCC, including 25 with PVTT (mainly Vp1-3) after successful DS and 20 with Vp1/2 PVTT without previous treatment. DS was attempted in 43, was successful in 27 (63%), and 25 underwent LDLT. Median alpha fetoprotein (AFP) at diagnosis and pre-LDLT were 78.1 ng/mL (3-58 200) and 55 ng/mL (2-7320), respectively. Mean DS to LDLT time was 10.2 weeks (5-16). Excluding 2 postoperative deaths, 1- and 5-year overall survival (OS) and recurrence-free survival (RFS) were 82%, 57%, and 77%, 51%, respectively, comparable to survival in 382 HCC patients without PVTT undergoing upfront LDLT (5-y OS 65%, P = 0.06; RFS 66%, P = 0.33, respectively). There was a trend toward better OS in DS+LDLT versus non-DS LDLT group (5-y OS/RFS-48%/40%). OS was significantly better than in HCC-PVTT patients receiving no intervention or palliative Sorafenib alone (1-y OS of 0%) or Sorafenib with TARE/SBRT (2-y OS of 17%) at our center during the study period. Initial AFP <400 ng/mL and AFP fall (initial minus pre-LDLT) >2000 ng/mL predicted better RFS; Grade III/IV predicted worse OS in DS patients.

CONCLUSIONS

HCC patients with PVTT can achieve acceptable survival with LDLT after successful DS. Low initial AFP level, a significant drop in AFP with DS and low tumor grade, favorably influence survival in these patients.

Expanding the Limits of Liver Transplantation for Hepatocellular Carcinoma: Is There a Limit?

Liver transplantation is a treatment option for hepatocellular carcinoma within Milan criteria. With careful selection practices, patients with larger tumors can do well with successful downstaging followed by liver transplantation and should not be excluded based on tumor size or number alone. When considering expanded criteria for hepatocellular carcinoma, however, survival outcomes after liver transplantation should be comparable with patients without hepatocellular carcinoma. Surrogate measures of tumor biology, such as α-fetoprotein, other biomarkers, and dynamic tumor behavior including response to locoregional therapy can aid in risk stratification of patients before liver transplantation.

Incorporating Tumor Biology to Predict Hepatocellular Carcinoma Recurrence in Patients Undergoing Living Donor Liver Transplantation Using Expanded Selection Criteria

Conventional selection criteria for liver transplantation (LT) in patients with hepatocellular carcinoma (HCC) are based on tumour size/number only, and do not consider vital surrogates of tumor biology such as alpha-fetoprotein (AFP) and tumor [¹⁸ F]fluorodeoxyglucose positron emission tomography ([¹⁸ F]FDG PET) avidity. We analyzed survival outcomes, and predictors of HCC recurrence in 405 patients with cirrhosis and HCC (HCC-cirr) who underwent living donor LT (LDLT) using our expanded selection criteria: no extrahepatic disease or major vascular invasion, irrespective of tumor size/number. Fifty-one percent patients had tumours beyond Milan, and 43% beyond the University of California San Francisco [UCSF] criteria. The 5-year overall survival (OS) and recurrence-free survival (RFS) were 64% and 70%, respectively. Three preoperatively available factors predicted recurrence: pre-LT AFP ≥100 ng/mL (P = 0.005; hazard ratio [HR], 2.190), tumor burden beyond the UCSF criteria (P = 0.001; HR, 2.640), and [¹⁸ F]FDG PET avidity (P = 0.004; HR, 2.442). A prognostic model based on the number and combination of the aforementioned preoperative risk factors was developed using a competing-risk RFS model. Three risk groups were identified: low (none or a single risk factor present, 9.3% recurrence), moderate (AFP ≥100 ng/mL and [¹⁸ F]FDG PET avidity, or beyond UCSF tumor and [¹⁸ F]FDG PET avidity, 25% recurrence), and high (AFP ≥100 ng/mL and beyond UCSF, or presence of all 3 risk factors, 46% recurrence). Acceptable long-term outcomes were achieved using our expanded selection criteria. Our prognostic model to predict recurrence based on preoperative biological and morphological factors could guide pretransplant management (downstaging versus upfront LDLT) with the aim of reducing post-LDLT recurrence.

Downstaging to Liver Transplant: Success Involves Choosing the Right Patient

Hepatocellular carcinoma is a rising indication for liver transplantation in the United States. Downstaging, defined as the reduction of tumor burden using local-regional therapy into Milan criteria, opens an avenue to access cure through transplant for patients who traditionally would not qualify. Approaching the selection of downstaging candidates through an assessment of hepatic function, staying within a modest expansion of tumor burden, and incorporation of serologic/imaging markers for tumor biology provide the best chance for successful downstaging. Following well-defined downstaging protocols with built-in failure criteria ensures excellent post-transplant outcomes.

A 2020 update on liver transplant for hepatocellular carcinoma

INTRODUCTION

Hepatocellular carcinoma is the most frequent liver tumor and is associated with chronic liver disease in 90% of cases. In selected cases, liver transplantation represents an effective therapy with excellent overall survival.

AREA COVERED

Since the introduction of Milan criteria in 1996, numerous alternative selection systems to LT for HCC patients have been proposed. Debate remains about how best to select HCC patients for transplant and how to prioritize them on the waiting list.

EXPERT OPINION

The selection of the best scoring system to propose in the context of LT for HCC is far to be identified. In this review, we analyze and categorize the various selection systems, assessing their roles in the different decisional phases.

Molecular Imaging and Therapy of Liver Tumors

Liver cancer is one of the top leading causes of mortality worldwide. Conventional imaging using contrast enhanced CT and MRI are currently the mainstay of oncologic imaging of the liver for the diagnosis and management of cancer. In the past two decades, especially since the advent of hybrid imaging in the form of PET/CT and SPECT/CT, molecular imaging has been increasingly utilized for oncologic imaging and the variety of radionuclide probes for imaging liver cancers have been expanding. Beyond the usual workhorse of FDG as an oncologic tracer, there is a growing body of evidence showing that radiolabeled choline tracers, C-11 acetate and other new novel tracers may have increasing roles to play for the imaging of liver tumors. On the therapy front, there have also been advances in recent times in terms of targeted therapies for both primary and secondary liver malignancies, particularly with transarterial radioembolization. The concept of theranostics can be applied to transarterial radioembolization by utilizing a pretreatment planning scan, such as Tc-99m macroaggregated albumin scintigraphy, coupled with post treatment imaging. Radiation dose planning by personalized dosimetric calculations to the liver tumors is also being advocated. This article explores the general trends in the field of nuclear medicine for the imaging and treatment of liver cancer above and beyond routine diagnosis and management.

Retinal dehydrogenase 5 (RHD5) attenuates metastasis via regulating HIPPO/YAP signaling pathway in Hepatocellular Carcinoma

Retinal dehydrogenase 5 (RDH5) is an important enzyme in the visual cycle. Several studies have reported that the RDH family may play crucial roles in tumor prognosis. However, the role of RDH5 in tumor prognosis is still unclear. We examined the mRNA level of RDH5 by using q-PCR in hepatocellular carcinoma (HCC) and adjacent non-cancerous tissues. The proliferation rate of HCC cells was detected by MTS assay, and the invasive ability was examined by transwell and scratch wound assays. The YAP protein localization and expression were visualized by immunofluorescence in two different cell lines. CpG islands in the promoter region were predicted by using the methprimer database. Clinical characteristics of a patient cohort data came from The Cancer Genome Atlas database. RDH5 was significantly downregulated in hepatocellular carcinoma tissues, and low RDH5 expression was associated with metastasis and poor patient prognosis. Functional assays revealed that the RDH5 promoter is methylated in HCC cell lines. Moreover, overexpressing RDH5 can suppress metastasis by reversing the epithelial-mesenchymal transition (EMT) process, and RDH5 also inhibits cell proliferation in HCC cell lines. Furthermore, suppressing RDH5 can activate the Hippo/YAP signaling pathway and promote the nuclear translocation of YAP. Clinical data demonstrated that RDH5 is an independent prognostic factor in HCC. In our study, we provided the first evidence that RDH5 plays a crucial role in suppressing proliferation and metastasis, and the RDH5 promoter is methylated in hepatocellular carcinoma. And as an important regulator, RDH5 can suppress the Hippo/YAP signaling pathway. Taken together, it revealed that RDH5 might be a potential therapeutic target in HCC patients.

Hepatocellular carcinoma recurrence after acute liver allograft rejection treatment: A multicenter European experience

BACKGROUND

During the last decades, several risk factors for the recurrence of hepatocellular carcinoma (HCC) after liver transplantation (LT) have been investigated. However, the impact of two important drivers of oncogenesis, namely the immunosuppression and the treatment of acute cellular rejection (ACR) have been marginally addressed. This study aimed at investigating the impact of ACR treatment on the incidence of tumor recurrence in a large European HCC-LT population.

METHODS

Seven hundred and eighty-one adult patients transplanted between February 1, 1985 and June 30, 2016 were retrospectively analyzed. After propensity score match, 116 patients treated for ACR using steroid boluses were compared with 115 patients who did not present any ACR or a histologic but clinical irrelevant ACR.

RESULTS

Steroid boluses treated patients had a 18-fold higher overall incidence of HCC recurrence than those non-treated patients (16.4% vs. 0.9%; P<0.0001). At multivariate Cox regression analysis, steroid boluses used to treat ACR were an independent risk factor for HCC recurrence (HR=14.2; 95% CI: 1.8-110.4; P = 0.010).

CONCLUSIONS

The decision to treat ACR as well as to reinforce immunosuppression load should be cautiously taken in view of the presented results. Prospective studies are needed to further elucidate the clinical impact of immunosuppression on HCC recurrence after transplantation.

18F-FDG PET/CT predicts microvascular invasion and early recurrence after liver resection for hepatocellular carcinoma: A prospective observational study

BACKGROUND

This study assessed the prognostic value of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) in the prediction of MVI and early recurrence following resection.

METHOD

This prospective study (ClinicalTrials.gov ID: NCT02145013) included 78 consecutive HCC patients who underwent 18F-FDG PET/CT before curative-intent resection from 2014 to 2017. Prognostic factors available before surgery for predicting MVI and early recurrence (≤2 years) were identified by univariate and multivariate analyses.

RESULTS

The 18F-FDG PET/CT result was positive in 30 (38%) patients. MVI was present in 33% (26/78) of specimens. Early recurrence occurred in 19% (14/74) of surviving patients. PET/CT positivity was the sole independent predictor of MVI (odds ratio [OR] = 3.6, 95% confidence interval [CI] = 1.1-11.2; p = 0.03), with a specificity and sensitivity for predicting MVI of 73% and 62%, respectively. Analysis of variables available before surgery showed that PET/CT positivity (hazard ratio [HR] = 5.8, 95% CI = 1.6-20.4; p = 0.006) and the male sex (HR = 6.6; 95% CI = 1.8-24.2; p = 0.005) were independent predictors of early recurrence.

CONCLUSION

18F-FDG PET/CT predicts MVI and early recurrence after surgery for HCC and could be used to select patients for neoadjuvant treatment.

Emerging role of 18F-fluorodeoxyglucose positron emission tomography for guiding management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of major causes of cancer mortality worldwide. For decades, ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET) has been widely used for staging, predicting prognosis, and detecting cancer recurrence in various types of malignant diseases. Due to low sensitivity of FDG PET for detecting intrahepatic HCC lesions, the clinical value of FDG PET in HCC patients has been limited. However, recent studies with diverse analytic methods have shown that FDG PET has promising role in aiding management of HCC patients. In this review, we will discuss the clinical role of FDG PET for staging, predicting prognosis, and evaluating treatment response in HCC. Further, we will focus on recent clinical studies regarding implication of volumetric FDG PET parameters, the significance of FDG uptake in HCC for selecting treatment and predicting treatment response, and the use of radiomics of FDG PET in HCC.

18F-fludeoxyglucose positron emission tomography for diagnosis of HCC: implications for therapeutic strategy in curative and non-curative approaches

Hepatocellular carcinoma (HCC) is a global health issue with increasing incidence and high mortality rate. Depending on the tumor load and extent of underlying liver cirrhosis, aggressive surgical treatment by hepatectomy or liver transplantation (LT) may lead to cure, whereas different modalities of liver-directed locoregional or systemic tumor treatments are currently available for a noncurative approach. Apart from tumor burden and grade of liver dysfunction, assessment of prognostic relevant biological tumor aggressiveness is vitally important for establishing a promising multimodal therapeutic strategy and improving the individual treatment-related risk/benefit ratio. In recent years, an increasing body of clinical evidence has been presented that ¹⁸F-fludeoxyglucose (¹⁸F-FDG) positron emission tomography (PET), which is a standard nuclear imaging device in oncology, may serve as a powerful surrogate for tumor invasiveness and prognosis in HCC patients and, thereby, impact individual decision making on most appropriate therapy concept. This review describes the currently available data on the prognostic value of ¹⁸F-FDG PET in patients with early and advanced HCC stages and the resulting implications for treatment strategy.

Role of pre-transplant 18F-FDG PET/CT in predicting hepatocellular carcinoma recurrence after liver transplantation

The last two decades have seen a paradigm shift in the selection of patients with hepatocellular carcinoma (HCC) for liver transplantation. Microvascular invasion and differentiation have been the most significant factors affecting post-transplant recurrence; however, because of inherent disadvantages of pre-transplant biopsy, histological criteria never gained popularity. Recently, the selection criteria evolved from morphological to biological criteria, such as biomarkers and response to loco-regional therapy. With the introduction of multimodality imaging, combination of computed tomography with nuclear medicine imaging, particularly, 18F-fluorodeoxyglucose positron emission tomography fulfilled an unmet need and rapidly became a critical component of HCC management. This review article will focus on the use of 18F-fluorodeoxyglucose positron emission tomography combined with computed tomography in the pre-transplant evaluation of HCC patients with special discussion on its ability to predict HCC recurrence after liver transplantation.

Transplantation for hepatocellular cancer: pushing to the limits?

Milan criteria (MC) represents the cornerstone in the selection of patients with hepatocellular cancer (HCC) waiting for liver transplantation (LT). MC represent the precursor of the scores based on the idea of "utility": in other terms, the scoring systems typically used in the field of LT oncology present the exclusive aim of selecting the cases with the best post-LT outcomes. However, some other scores have been proposed specifically investigating the risk of death or tumour progression during the waiting list. In this case, the selection process is connected with the idea of "priority": patients at higher risk for drop-out (DO) should be selected, prioritising them or, conversely, deciding to de-list them due to the high risk of post-LT futile transplant. Lastly, models based on the concept of "benefit", namely the balancing between priority and utility, have been recently created. The present review aims to examine these three different types of scoring systems, trying to underline their pro and cons in the allocation process of HCC patients.

Combining 18F-FDG positron emission tomography with Up-to-seven criteria for selecting suitable liver transplant patients with advanced hepatocellular carcinoma

The Up-to-seven (UTS) criteria (sum of tumor size and number not exceeding 7) for indicating liver transplantation (LT) in hepatocellular carcinoma (HCC) were originally based on explant pathology features and absence of microvascular invasion (MVI). ¹⁸F-fludeoxyglucose (¹⁸F-FDG) positron emission tomography (PET) was shown to indicate the risk of MVI and tumor recurrence. The aim of this study was to analyze the prognostic significance of the clinical UTS criteria when being combined with PET-status of the tumor. Data of 116 liver transplant patients were subject to retrospective analysis. Five-year recurrence-free survival (RFS) rates in patients meeting (n = 85) and exceeding (n = 21) the radiographic UTS criteria were 81% and 55.1%, respectively (p = 0.014). In the UTS In subset, RFS was significantly better in PET-negative (94.9%) than in PET-positive patients (48.3%; p < 0.001). In the UTS Out subset, 5-year RFS rates were 87.1% and 19% in patients with non- ¹⁸F-FDG-avid and ¹⁸F-FDG-avid tumors (p < 0.001), respectively. Positive PET-status was identified as the only independent clinical predictor of tumor recurrence in beyond UTS patients (Hazard ratio [HR] 19.25; p < 0.001). Combining radiographic UTS criteria with FDG-PET may safely expand the HCC selection criteria for LT.

18F-FDG-PET for Assessing Biological Viability and Prognosis in Liver Transplant Patients with Hepatocellular Carcinoma

Liver transplantation (LT) has become standard of care in patients with non-resectable early stage hepatocellular carcinoma (HCC) in liver cirrhosis. Currently, patient selection for LT is strictly based on tumor size and number, provided by the Milan criteria. This may, however, exclude patients with advanced tumor load but favourable biology from a possibly curative treatment option. It became clear in recent years that biological tumor viability rather than tumor macromorphology determines posttransplant outcome. In particular, microvascular invasion and poor grading reflect tumor aggressiveness and promote the risk of tumor relapse. Pretransplant biopsy is not applicable due to tumor heterogeneity and risk of tumor cell seeding. ¹⁸F-fludeoxyglucose (¹⁸F-FDG) positron emission tomography (PET), an established nuclear imaging device in oncology, was demonstrated to non-invasively correlate with unfavorable histopathologic features. Currently, there is an increasing amount of evidence that ¹⁸F-FDG-PET is very useful for identifying eligible liver transplant patients with HCC beyond standard criteria but less aggressive tumor properties. In order to safely expand the HCC selection criteria and the pool of eligible liver recipients, tumor evaluation with ¹⁸F-FDG-PET should be implemented in pretransplant decision process.

Living donor liver transplantation for hepatocellular carcinoma achieves better outcomes

Liver transplantation (LT) for hepatocellular carcinoma (HCC) at Kaohsiung Chang Gung Memorial Hospital mainly relies on live donor LT (LDLT). Owing to taking the risk of LD, we are obligated to adopt strict selection criteria for HCC patients and optimize the pre-transplant conditions to ensure a high disease-free survival similar to those without HCC, even better than deceased donor LT (DDLT). Better outcomes are attributed to excellent surgical results and optimal patient selection. The hospital mortality of primary and salvage LDLT are lower than 2% in our center. Although Taiwan Health Insurance Policy extended the Milan to University of California, San Francisco (UCSF) criteria in 2006, selection criteria will not be consolidated to take into account only by the morphologic size/number of tumors but also by their biology. The criteria are divided into modifiable image morphology, alpha fetoprotein (AFP), and positron emission tomography (PET) scan with standard uptake value (SUV) and unmodifiable unfavorable pathology such as HCC combined with cholangiocarcinoma (CC), sarcomatoid type, and poor differentiation. Downstaging therapy is necessary for HCC patients beyond criteria to fit all modifiable standards. The upper limit of downstaging treatment seems to be extended by more effective drug eluting transarterial chemoembolization in cases without absolute contraindications. In contrast, the pitfall of unmodifiable tumor pathology should be excluded by the findings of pretransplant core biopsy/resection if possible. More recently, achieving complete tumor necrosis in explanted liver could almost predict no recurrence after transplant. Necrotizing therapy is advised if possible before transplant even the tumor status within criteria to minimize the possibility of tumor recurrence. LDLT with low surgical mortality in experienced centers provides the opportunities of optimizing the pre-transplant tumor conditions and timing of transplant to achieve better outcomes.